JPH1141556A - Digital photograph image pickup device provided with image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a digital photograph image pickup device without requiring a separate computer for processing by providing a compression means that generates a digital image being a compressed image of an actual scene and a memory that stores the compressed digital image in the device. SOLUTION: This device is provided with a lens 110, an aperture 115, and a processing means 140 that obtains a digital image processed from a digital image obtained by an optical sensor 120 and a processing parameter corresponding to the image. The processing means 140 provides an output of the digital image compressed and processed by a compression means 130 in a 1st operating state, and provides an output of the digital image compressed and obtained by the compression means 130 and the processing parameter stored in the memory 135 in a 2nd operating state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital photographing apparatus, and more particularly to a means for acquiring a digital image representing an actual scene, a compressing means for forming a compressed digital image, and a compressed digital image. And a memory for storing the image data.

[0002]

2. Description of the Related Art In a digital photographing apparatus, particularly a digital still camera (DSC), an image of an actual scene is represented by a matrix of digital values (digital images). Digital images can be printed without the need for printing and subsequent digitization of the photo on a physical support.
It can be transferred to a computer, transmitted over a network, or displayed on a television screen. The digital images transferred to the computer are processed using a suitable program and can be printed directly by the user. This saves film and development allowance and reduces the time to create a photo.

[0003]

Generally, digital images undergo a compression process to increase the number of images that can be stored simultaneously in the camera's internal memory. In cameras that use proprietary compression algorithms, such as the camera developed by Kodak, for example, digital images typically acquired partially by optical sensors are immediately compressed and then internalized to optimize the compression process. Stored in memory. The disadvantage of this method is that it always requires a computer to decompress and possibly process the digital image and to exchange the digital image with a user using other devices.

In a different known structure using a standard compression algorithm such as the JPEG algorithm,
The partial data acquired by the light sensor is interpolated to generate the actual digital image. Thereafter, the digital image is compressed and stored in internal memory.
The compressed image can be sent directly to another user or transmitted to a computer and decompressed and displayed by most available image processing devices. However, this method also requires a computer to be able to decompress and process the digital images and send them to another device. The aim of the invention is to avoid the disadvantages mentioned above.

[0005]

SUMMARY OF THE INVENTION To this end, the present invention comprises a means for acquiring a digital image representing a real scene; a means for forming a compressed digital image; A digital photographing device comprising: a memory for storing a digital image, comprising: processing means for obtaining a processed digital image and corresponding processing parameters from the acquired digital image, the processing means comprising: a first operating state; Providing, as an output, the processed digital image to be compressed by the compression means, and outputting the obtained digital image to be compressed by the compression means and the processing parameters to be stored in the memory in a second operating state. It is characterized by being supplied as.

The device of the present invention processes digital images directly internally, thus eliminating the need for an external computer.

This device does not depend on the technology used to compress the digital image and has an architecture suitable for use of any proprietary or standard algorithm.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the digital photographing device according to the present invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying drawings. Note that this embodiment is merely an example and does not limit the present invention. With particular reference to FIG. 1, there is shown a digital photographing apparatus 100, particularly constituted by a digital still camera. However, the invention is also suitable for use in various applications, such as digital video cameras and portable scanners. The digital camera 100 converts the image of the actual scene
And a digital image acquisition device that includes a set of lenses 110 and an aperture 115 for supplying to the lens. When a photo is taken
The aperture 115 is opened and the light focus corresponding to the image to be acquired is
Tied on top. Generally, light sensor 120 includes a charge coupled device (CCD). A CCD is an integrated circuit that includes a matrix of photosensitive cells, each of which produces an electrical signal (eg, voltage) of an intensity proportional to the exposure of the cell. The electrical signal generated by each photosensitive cell is converted by a suitable analog-to-digital converter (A / D) to a digital value representing a pixel of the image. To have a color image, the light is red, blue and green (ie, RG
Decomposed into various components typically corresponding to B). RG relative to each pixel, corresponding to each pixel area of the image
There are three cells that are sensitive to the wavelengths of red, blue and green light, respectively, so as to obtain a value indicating the B component. Generally, light sensors are used to reduce the number of photosensitive cells.
120 does not detect all of the RGB components in each pixel.
For example, the G component is detected in only half of the pixels, and only the R and B components are detected in the other half of the pixels. In the digital image thus obtained, there is a blur which is removed as described below by interpolation of the partial data detected by the optical sensor 120. Device 125 controls the digital image acquisition process and
Send appropriate control signals to 110 and aperture 115.

The camera 100 is capable of producing a compressed digital image (eg, by reducing the amount of associated data to a fraction of a tens) and later compressing the compressed image from compression. It includes a compression / decompression device 130 which can be decompressed. Camera 100 according to the present invention
The compression / decompression device 130 may use either a proprietary compression algorithm such as that developed by Kodak or a standard compression algorithm such as the JPEG algorithm. The compression / decompression device 130 includes a memory 135 for storing digital images in a compressed form.
It is connected to the. Generally, the memory 135 is a dynamic memory having a capacity of several megabytes and capable of storing tens of compressed digital images. In other cases, the memory is a flash EPROM that stores data without power, and additional external memory cards with tens of megabytes of capacity may also be used.

[0010] The image processing device (ie, IPU) 140 includes:
A first input (IN1) and a second input (IN2) are provided in the camera 100 according to the present invention and connected to the compression / decompression device 130 and the optical sensor 120, respectively. The first output (OUT1) and the second output (OUT2) are connected to a compression / decompression device 130 and an acquisition control device 125, respectively. The optical sensor 120 is also connected directly to the compression / decompression device 130 so that the IPU 140 can be bypassed. The IPU 140 is, for example, a personal computer (P
C) Third output (150) connected to an interface device 145 for connection to an external device such as 150, a television set 155 or a modulator / demodulator (modem) 160 for connection to a network such as the Internet. OU
T3). The interface device 145 is also connected to a viewfinder 165, which is preferably formed by a liquid crystal display (ie, LCD). The finder 165 operates as an observation finder when taking a picture in order to reproduce the acquired image. The viewfinder 165 also preferably allows previewing of the photo. In this case, the user can select the best image and immediately delete the unnecessary one. It should be noted that in a preferred embodiment of the invention, the compression / decompression unit 130 and the IPU 140 (and possibly also the interface 145) are manufactured in an integrated form on a single chip of semiconductor material. .

The central processing unit (ie, CPU) 170
Different operations of the various elements of digital camera 100 are controlled by appropriate pulses. CPU 170 includes an input device 17 comprising, for example, a set of push buttons that allow a user to select various functions of digital camera 100.
Connected to 5.

Referring to FIG. 2 (the elements shown in FIG. 1 are indicated by the same reference numerals or symbols), the input IN2
Are connected to a device 205 for enhancing the output of the optical sensor 120. In general, the apparatus 205 corrects the acquired digital image by an interpolation process, estimates the missing RGB components to remove blur, and increases the number of pixels to increase the resolution according to known prior art. Interpolator 205
Is connected to a first input of a multiplexer circuit 210, the second input of which is directly connected to the input IN1 of the IPU 140. Multiplexer 210 is coupled to the appropriate control signal CO-D supplied to the select control input of the multiplexer.
One of the two inputs is transmitted to the output of the multiplexer according to ECOD. The output of the multiplexer 210 is connected to a segmenter 220 which divides the digital image into several regions and estimates various parameters such as high frequency content, average luminosity for each region. An apparatus 225 for automatically determining focus (autofocus) and automatically determining exposure (autoexposure) is connected to the output of the multiplexer 210 and the output of the segmenter 220. The values determined by the segmenter 220 are appropriately weighted based on the characteristics of the image to determine and determine optimal focus and exposure parameters. For example, in the literature ("A New Algorithm for Exposure CON
TROL Based on Fuzzy Logic for Video Camera ", IEEE
Transactions on Consumer Electronics, Vol. 38, No. 3,
p.617-623, August 1992, and Haruki et al. "
Video Camera System Using Fuzzy Logic ", IEEE Tra
nsactions on Consumer Electronics, Vol. 38, No. 3, p. 62
Preferably, the "fuzzy" logic technique described in U.S. Pat. No. 4-634, August 1992) is used for this. The output of the autofocus and autoexposure unit 225 is connected to the output OUT2 of the IPU 140 to provide these parameters to the acquisition control unit 125.

The signal output by the multiplexer 210 is also provided to a computing device 230 which produces a histogram of the frequency distribution of the image. Automatic exposure / compensation device 235
Are connected to the output of the multiplexer 210 and the output of the computing device 230. The digital image is modified based on the data in the histogram generated by the computing device 230 to correct for exposure problems, such as backlighting or excessive front lighting. The white balance device 240 is connected to the output of the exposure correction device 235 and the output of the calculation device 230. The digital image is further modified to correct for a color shift of light shifting in the red direction (reddish) or light shifting in the blue direction (bluish) depending on the color temperature of the light source. As in the case described above, "fuzzy" logic technology is preferably used in these devices. However, it should be noted that the present invention can be implemented with different or more devices that control the digital image acquisition process.

The IPU 140 also includes a noise level estimator 245 connected to the output of the exposure compensator 235 and the output of the white balance device 240. The noise level estimator 245 generates an estimate of noise depending on the luminosity of the digital image. The noise reduction device 250 is connected to the output of the white balance device 240 and the output of the evaluation device 245. The digital image is based on an assessment made by the device 245 to dynamically reduce the effects of noise introduced by the optical sensor, depending on the noise level and the spatial properties of the image, for example in the literature (Mr. Nakajima et al. By "A
New Noise Reduction System for Video Camera ", IEE
E Transactions on Consumer Electronics, Vol. 37, No.
3, p.213-219, August 1991 and by G.De Haan et al.
"MemoryIntegrated Noise Reduction IC for Televis
ion ", IEEE Transactions on Consumer Electronics, Vo
l.42, No. 2, p. 175-181, May 1996). In this case, it should be noted that the noise correction introduced by the optical sensor depends on the magnitude of the exposure correction made by the device 235, since it depends on the light intensity of the image.

The device 250 is connected in cascade with the color tone correcting device 255. This device 255 corrects for the alteration of one or more color categories (depending on the type of illumination) without changing the other colors of the image. In particular, this is described, for example, in the literature ("Color Enhancement of TV Picture Using R"
BG Sensor ", IEEE Transactions on Consumer Electron
ics, Vol. 42, No. 2, pp. 182-191, May 1996), the quality of the skin tones of portraits or the display of sky and grass overlooking the panorama. To improve. A device 260 connected to the output of the tonal correction device 255
Various special effects such as, for example, a mist effect, a "fume" effect, etc., are applied to the digital image. However, it should be noted that the present invention can be implemented with different or more devices that improve the quality of the digital image.

The digital image thus processed by the devices 230 to 260 is the output TEMP2 of the special effects device 260.
Supplied in. The output TEMP2 of the device 260 and the output TEMP1 of the interpolator 205 are respectively connected to first and second inputs of a multiplexer circuit 265, which transmits one of the two inputs to its output. And one of its inputs is connected to the control signal CO-DECOD supplied to the select control input of the multiplexer.
Connected to output OUT1 of PU140.

The signal at the input IN1 of the IPU 140 and the control signal CO-DECOD are also supplied to an AND logic unit 270, whose output is the discrete cosine transform (ie, DC) used in the JPEG compression algorithm.
T) connected to an apparatus 275 for correcting the alterations (such as the mosaic effect) introduced by the coding method. It should be noted that it is advantageous to use AND device 270 to prevent any malfunction of device 275 due to non-coherent input signals. An example of the structure of the device 275 is described in the literature ("Post-Filtering Methods for Reducing
Blocking Effects from Coded Images ", IEEE Transact
ions on Consumer Electronics, Vol.40, No.3, p.521-52
6, August 1994).

The IPU 140 is connected to the output TE of the special effect device 260.
The first connected to the MP2 and the output of the device 275, respectively.
And another multiplexer circuit 280 having a second input and a select control input to which the control signal CO-DECOD is supplied. The output of the multiplexer 280 is connected to a filter 285, the output of which is the output of the IPU 140.
Directly connected to OUT3. The filtering device 285 filters the processed digital image according to the selected external device. For example, if the external device is a PC that is typically connected to a printer to play back pictures, the filtering device 28
5 increases the resolution of the digital image by the interpolation process. It may also be useful to use this process to further process digital images, for example, digital zoom, changing the dimensional ratio (eg, from 4: 3 to 16: 9). Alternatively, if the external device is a television set, the digital image is filtered to compensate for the loss of sharpness in the image with highly saturated colors, typically with a gamma correction function provided on the digital image. Device 285
Is also used to filter the digital image to be sent to the viewfinder (165 in FIG. 1), for example, by applying control over the dynamic range of the image. A control unit (not shown) controls various functions of the IPU 140 and controls communication with the CPU (170 in FIG. 1).

To illustrate the operation of the camera, assume that a picture has been taken. If the compression / decompression device 130 uses a standard algorithm (JPEG),
The control signal CO-DECOD adopts a first value (for example, 00). In this case, the multiplexer 210 transmits as output the signal provided at the output TEMP1 and constituted by the digital image acquired by the optical sensor 120 and appropriately interpolated by the device 205. This digital image is processed by devices 225 through 260 according to the function selected by the user via the input device (175 in FIG. 1). The digital image thus processed is supplied to output TEMP2,
Transmitted to output OUT1 by multiplexer 265. The processed digital image is then compressed by the device 130 and stored in the camera memory (135 in FIG. 1).

When the compression / decompression device 130 uses a proprietary algorithm (KODAK), the control signal CO-DECOD
Adopts a second value (for example, 01). In this case, the signal provided at output TEMP1 is processed in the same way as in the previous case. Multiplexer 265 transmits the signal at output TEMP1 to output OUT1, which signal is constituted by the digital image acquired by light sensor 120 and interpolated by device 205, which image is compressed and stored. The processing parameters calculated by the IPU 140 during the previous processing steps are also supplied to the compression / decompression unit 130 and stored in a suitable structure associated with the compressed digital image, in particular these parameters are supplied. At the beginning of a separate file, or a file containing a compressed digital image, for example in the form of "FlashPix".

In both operating states of the IPU 140 described above, the processed digital image provided at the output TEMP2 is output (by the device 285) by the multiplexer 280.
It is effective that the data is transferred to OUT3 and then transferred to the finder (165 in FIG. 1) by the interface device 145. It should be noted that if proprietary algorithms were used, the architecture of the present invention would allow a processed digital image corresponding to the final work to be provided to the user in this situation as well.

In a preferred embodiment of the present invention, the IP
U140 can employ two more operating states to transmit the digital image decompressed to the external device. If a standard compression algorithm is used, the control signal CO-DECOD adopts a third value (eg, 10). In this case, the digital image supplied to input IN1 and processed (read from memory 135 in FIG. 1)
And the signal decompressed from the compression is transmitted by the AND device 270 to the correction circuit 275. The processed digital image is manipulated by device 275 and applied to the input of a multiplexer 280, which transmits it to its output, which is then applied by filtering device 285 to the output OUT3 of IPU 140. Finally, output OUT3
Is transmitted to the interface device 145 to reach the selected external device.

When a proprietary compression algorithm is used, the control signal CO-DECOD adopts a fourth value (eg, 11). In this case, the multiplexer 210 provides a signal stored at the input IN1 which is composed of the acquired digital image (read from the memory 135 of FIG. 1) and which has been decompressed by the device 130 and previously stored. It is transmitted as output with the corresponding processing parameters. Digital images are generated according to these parameters on devices 230-26.
Handled by 0. The digital image thus processed is supplied to an output TEMP2. Multiplexer 280 forwards this signal to its output, which is then forwarded to the selected external device as described above. It should be noted that in this embodiment of the invention, the camera can be connected directly to any device, such as a printer, without the need for an external computer.

Of course, to satisfy unforeseen and specific needs, those skilled in the art will recognize numerous modifications and variations that fall within the scope of the invention, which is limited by the appended claims. May be added to the digital photographing device that has been used.

[Brief description of the drawings]

FIG. 1 is a basic block diagram of a digital photographing device according to the present invention.

FIG. 2 is a block diagram showing the structure of the image processing apparatus of FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Rinaldo Poluzzi, Italy, 20125 Piazza Istria, Milan 2 (72) Inventor Fabrizio Airoldi, Italy, 28040 Feriolo (Verbania), Via Calletto 19

Claims (14)

[Claims] 1. A digital photographic apparatus comprising: means for acquiring a digital image representing an actual scene; compression means for forming a compressed digital image; and memory for storing the compressed digital image. Processing means for obtaining a processed digital image and corresponding processing parameters from the acquired digital image,
The processing means provides as output a processed digital image to be compressed by the compression means in a first operating state and an acquired digital image to be compressed by the compression means in a second operating state; A digital photographing device, characterized in that it supplies processing parameters to be stored as outputs. 2. The image processing apparatus according to claim 1, further comprising: means for restoring the compressed digital image from the compression.
Receiving a processed digital image obtained from the compressed digital image to supply the processed digital image to an external device in the fourth operating state, obtaining a processed digital image in a fourth operating state, The apparatus of claim 1, wherein the apparatus receives an acquired digital image obtained from the compressed digital image to provide the processed digital image to an external device, and corresponding processing parameters. 3. Apparatus according to claim 1, further comprising a finder for displaying the processed digital image. 4. The processing means comprises a first device for generating a histogram of a frequency distribution of the acquired digital image, and a second device for correcting the exposure of the acquired digital image according to the histogram. Claims 1 to 3
An apparatus according to any one of the preceding claims. 5. Apparatus according to claim 4, wherein the processing means comprises a third device for adjusting the white balance of the acquired digital image according to the histogram. 6. The processing device comprises a fourth device for estimating the noise level of the acquired digital image and a fifth device for reducing the noise of the acquired digital image according to the estimate. Apparatus according to any one of the preceding claims. 7. Apparatus according to claim 1, wherein the processing device comprises a sixth device for correcting one or more tones of the acquired digital image. 8. A processing device, wherein the processing device divides the acquired digital image into a plurality of regions and calculates an amount associated with each region, and automatically adjusts the focus and exposure of the device according to the amounts. The apparatus according to any one of claims 1 to 7, further comprising: an eighth apparatus that determines the following. 9. The processing device according to claim 2, wherein the processing device comprises a ninth device for correcting alterations in the processed digital image obtained from the compressed digital image.
Item. 10. A tenth device for filtering a processed digital image to be supplied to a finder and for filtering the processed digital image to be supplied to an external device depending on the external device. The device according to any one of claims 2 to 9, comprising: 11. An obtaining means for correcting a blur of an image,
Apparatus according to any one of the preceding claims, comprising an eleventh apparatus for increasing the resolution of an acquired digital image. 12. Apparatus according to claim 2, wherein the compression means, the compression decompression means and the processing means are formed on a single chip of semiconductor material. 13. The device according to claim 1, wherein the device is a digital still camera. 14. An apparatus comprising a processing means used in the digital photographing apparatus according to claim 1. Description: